Event Notification Report for May 23, 2017
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/22/2017 - 05/23/2017
Power Reactor
Event Number: 52768
Facility: COOPER
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: RANDY KOUBA
HQ OPS Officer: JEFF HERRERA
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: RANDY KOUBA
HQ OPS Officer: JEFF HERRERA
Notification Date: 05/23/2017
Notification Time: 15:57 [ET]
Event Date: 05/23/2017
Event Time: 08:30 [CDT]
Last Update Date: 05/23/2017
Notification Time: 15:57 [ET]
Event Date: 05/23/2017
Event Time: 08:30 [CDT]
Last Update Date: 05/23/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
JEREMY GROOM (R4DO)
JEREMY GROOM (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
LOSS OF METEOROLOGICAL TOWER PRIMARY AND BACKUP COMMUNICATION EQUIPMENT
"This notification is being made due to a loss of emergency assessment capability in accordance with 10 CFR50.72(b)(3)(xiii). On [May, 23, 2017] at 0830 (CDT), the meteorological tower primary and backup communication equipment failed, which resulted in a loss of meteorological data to the plant. Information technology and communications personnel investigated and restored the primary system to service. Meteorological data to the plant was restored at 0925 on [May 23, 2017].
"The NRC Senior Resident Inspector has been informed."
"This notification is being made due to a loss of emergency assessment capability in accordance with 10 CFR50.72(b)(3)(xiii). On [May, 23, 2017] at 0830 (CDT), the meteorological tower primary and backup communication equipment failed, which resulted in a loss of meteorological data to the plant. Information technology and communications personnel investigated and restored the primary system to service. Meteorological data to the plant was restored at 0925 on [May 23, 2017].
"The NRC Senior Resident Inspector has been informed."
Power Reactor
Event Number: 52769
Facility: SEQUOYAH
Region: 2 State: TN
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: ROBERT CAMENISCH
HQ OPS Officer: STEVE SANDIN
Region: 2 State: TN
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: ROBERT CAMENISCH
HQ OPS Officer: STEVE SANDIN
Notification Date: 05/24/2017
Notification Time: 04:10 [ET]
Event Date: 05/23/2017
Event Time: 23:30 [EDT]
Last Update Date: 05/24/2017
Notification Time: 04:10 [ET]
Event Date: 05/23/2017
Event Time: 23:30 [EDT]
Last Update Date: 05/24/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
10 CFR Section:
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
JAMIE HEISSERER (R2DO)
JAMIE HEISSERER (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 2 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
ALL FOUR EDGs AUTOSTARTED DURING TRANSFER OF SHUTDOWN BOARD TO NORMAL POWER SOURCE FOR UNIT 2 TESTING
"On May 23, 2017 at 2330, while transferring 2A-A 6.9 kV Shutdown Board from its alternate power source to its normal power source in support of outage testing, a failure occurred which resulted in the loss of the Shutdown Board, emergency start of all 4 Emergency Diesel Generators (EDGs), and required the manual emergency stop of 2A-A EDG.
"During transfer of the 2A-A 6.9kV Shutdown Board, the hand switch for the normal feeder breaker on the shutdown board was being maintained in the 'CLOSE' position while the alternate feeder breaker hand switch was placed in 'TRIP.' As expected, the alternate feeder breaker opened and the normal feeder breaker closed. However, the upstream supply breaker to the normal feeder breaker immediately tripped due to an overcurrent relay actuation on a single phase. As a result, the 2A-A 6.9 kV Shutdown Board deenergized, initiating a blackout signal which started all 4 of the station's EDGs. During board stripping (opening of all feeder and load breakers, to prepare the board for automatic reenergization from the EDG), the normal feeder breaker to the Shutdown Board failed to trip. This failure to trip prevented the emergency feeder breaker in the output of 2A-A EDG from closing, in accordance with interlock logic. As a result, 2A-A 6.9 kV Shutdown Board remained deenergized which prevented the cooling water supply valve for the EDG from opening due to loss of motive power. This lack of cooling caused operators to emergency stop the 2A-A EDG.
"Power was restored to the Shutdown Board on May 24, 2017 at 0037.
"Unit 1 is currently stable in Mode 1, at 100% power and Unit 2 is stable in Mode 5 with RCS at 164 F and 340 psig.
"The cause of the breaker trip on overcurrent and the failure of the normal feeder to trip on load shedding are under investigation.
"This event had no impact on the health and/or safety of the public. The NRC Resident Inspector has been notified."
"On May 23, 2017 at 2330, while transferring 2A-A 6.9 kV Shutdown Board from its alternate power source to its normal power source in support of outage testing, a failure occurred which resulted in the loss of the Shutdown Board, emergency start of all 4 Emergency Diesel Generators (EDGs), and required the manual emergency stop of 2A-A EDG.
"During transfer of the 2A-A 6.9kV Shutdown Board, the hand switch for the normal feeder breaker on the shutdown board was being maintained in the 'CLOSE' position while the alternate feeder breaker hand switch was placed in 'TRIP.' As expected, the alternate feeder breaker opened and the normal feeder breaker closed. However, the upstream supply breaker to the normal feeder breaker immediately tripped due to an overcurrent relay actuation on a single phase. As a result, the 2A-A 6.9 kV Shutdown Board deenergized, initiating a blackout signal which started all 4 of the station's EDGs. During board stripping (opening of all feeder and load breakers, to prepare the board for automatic reenergization from the EDG), the normal feeder breaker to the Shutdown Board failed to trip. This failure to trip prevented the emergency feeder breaker in the output of 2A-A EDG from closing, in accordance with interlock logic. As a result, 2A-A 6.9 kV Shutdown Board remained deenergized which prevented the cooling water supply valve for the EDG from opening due to loss of motive power. This lack of cooling caused operators to emergency stop the 2A-A EDG.
"Power was restored to the Shutdown Board on May 24, 2017 at 0037.
"Unit 1 is currently stable in Mode 1, at 100% power and Unit 2 is stable in Mode 5 with RCS at 164 F and 340 psig.
"The cause of the breaker trip on overcurrent and the failure of the normal feeder to trip on load shedding are under investigation.
"This event had no impact on the health and/or safety of the public. The NRC Resident Inspector has been notified."